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18240020 = 2257011301
BaseRepresentation
bin100010110010…
…1001000010100
31021022200121022
41011211020110
514132140040
61450540312
7311015621
oct105451024
937280538
1018240020
11a328aa7
126137698
133a18316
1425cb348
1519046b5
hex1165214

18240020 has 24 divisors (see below), whose sum is σ = 38388168. Its totient is φ = 7280000.

The previous prime is 18240007. The next prime is 18240023. The reversal of 18240020 is 2004281.

It can be written as a sum of positive squares in 4 ways, for example, as 414736 + 17825284 = 644^2 + 4222^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18240023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13370 + ... + 14670.

It is an arithmetic number, because the mean of its divisors is an integer number (1599507).

Almost surely, 218240020 is an apocalyptic number.

18240020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18240020 is an abundant number, since it is smaller than the sum of its proper divisors (20148148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18240020 is a wasteful number, since it uses less digits than its factorization.

18240020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2011 (or 2009 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 18240020 is about 4270.8336422764. The cubic root of 18240020 is about 263.2338708208.

The spelling of 18240020 in words is "eighteen million, two hundred forty thousand, twenty".

Divisors: 1 2 4 5 10 20 701 1301 1402 2602 2804 3505 5204 6505 7010 13010 14020 26020 912001 1824002 3648004 4560005 9120010 18240020